The overall purpose of this research is to evaluate the long term outcomes of a theory driven and randomized trial (LIFT) that was designed to prevent the development of conduct disorders and other associated problems in children and adolescents. The intervention was tested for two age groups: children entering first and children entering fifth grades. During the current three year funding period, we demonstrated significant immediate impacts on three key antecedents targeted by the intervention; in addition, analyses of data collected for three years following the intervention, presented in this proposal, provide evidence that the intervention is producing preventive or delaying effects on a range of serious problem behaviors for the fifth grade intervention group, and on the development of disruptive behavior patterns in the first grade intervention group. On the basis of the progress and promising findings during the present funding period, we propose a five year continuation project to continue to follow this sample (approximately 650 boys and girls) as the young subjects develop into the peak period for anti-social and delinquent behavior, and as the older subjects make the transition into young adulthood. The specific aims for the proposed five year funding period are as follows: to continue conducting yearly assessments of the three cohorts until the younger subjects reach 10th grade, and the older subjects are two years post high-school; to carry out analyses to examine the effects of the intervention on developmental trajectories, subsequent conduct problems, substance use and emotional problems, and school and workplace adjustment; to carry out analyses to examine the effects of the intervention on the antecedents targeted, the relationships between effects on immediate antecedents and subsequent child problems, and subsequent antecedents specified in the underlying developmental model; and to carry out analyses to examine variations in impact associated with the presence of initial and subsequent risk variables, intervention dosage and utilization of services over the course of development.